Are you leaving your Facebook house unlocked?

Facebook is inviting investors to take a good look at the company this week ahead of its stock being traded around May 18th.

But Facebook users may not be taking a very good look at themselves. New research from Consumer Reports says millions of Americans share their birth date with the whole world on Facebook that could be used by identity thieves. Or they talk about being out of town, which is an invitation to burglars.

Jeff Fox of Consumer Reports says it's not just criminals who comb through your postings.

Jeff Fox: There's a company called Social Intelligence whose entire business consists of scavenging through social network posting for companies and the government and then there's the government itself, so for example, whether it was an insurance issue regarding disability or workman's compensation claim, or something you disclosed about income or whatever, for an insurance company or the IRS to see that you’re actually doing something of course, is probably something you don't want.

A lot of that information could be safe if you manage your privacy settings carefully. But...

Fox: We project that 13 million people have never used the settings, either they don't know about it or just not bothered to use them. We also found that more than one in four Facebook users share almost all their wall posts beyond their friends, which is a wide audience. That's risky because once you go outside your circle of friends you really don't know who's looking at it.

Of course, Facebook is more than just updates. Chester Wisniewski of the security firm Sophos says you may be leaving other doors unlocked.

Chester Wisniewski: More scary to me is that something like 37 percent, which I think is like 40 million people, have never adjusted the settings related to things that apps can do on Facebook, and apps can often access your information even if you don't use the app, so if your friends play "Farmville," their version of "Farmville" can actually access your profile and look at your personal data.

Remember what Spiderman says: With great power comes great responsibility.

Wisniewski: We have the tools now to tell more of the world than ever before about these types of events, and they are exciting events that we want to share, but we should probably restrain ourselves to sharing it with the same people we would have traditionally shared it with before there was a Facebook. Because the problem is we have to retrain our banks, our credit card companies and everyone else that maybe our birth date isn't the most secure thing to use to verify our identity, but in the meantime, they are using it that way.

For now, Jeff Fox says lock up your past.

Fox: Strongest thing I urge people to do is, Facebook has something you could use in 30 seconds that could convert all conversations you've had in the last five years to friends only.

Moe: That’s in the privacy settings?

Fox: Yes. It says limit your old posts. You do that, everything you've said on your wall since you joined Facebook would only be for friends.

Time for a Tech Report vocabulary word: Microsub. As in itty-bitty submarine. You may hear a lot more about the Microsub in the near future but you probably won't see them because they'll be ten times smaller than the width of a human hair.

New research indicates Microsubs could be built and deployed to oil spills to gather up oil particles and then deposit them somewhere safe. Those subs would totally get high fives from dolphins if the dolphins could even see the subs and if either the dolphins or the subs had fingers to do a high five with.

And get this: the subs are propelled by bubbles created from the oxidation of hydrogen peroxide.